It's not really fair to call it "studies" in quotations. It's better described as software micro-updates which can be progressively deployed in case the change has a regression. They do little more than enable/disable features already shipped in the binary you're running.

In my own browser, if I go to about:studies, I have two Studies running. One is the hotfix for the add-on signing issue. The other is:

  prefflip-push-performance-1491171 • Active
  This study sets dom.push.alwaysConnect to false.

If you equate that to a camera hidden in your TV, you might want to consider giving up whatever drugs you're on.